Basically, if a family of crows finds a dead crow, they all sit in a tree nearby all staring at the body, making no noise at all. They can last up to several hours, and without any signal, they all fly away at once and never look back.

Thats kinda creepy....
Have you heard what happens to dogs when their owners own several dogs and one dies? Unless they have seen the other dogs dead body and are given a chance to investigate it and confirm it's dead for themselves they will often wander around the house for weeks looking for their lost friend.